1. Field of the Invention
The present invention relates to a method of vulcanizing pneumatic vehicle tires where the tire beads, in the mounted state, are disposed on the radially inner periphery of a rim next to the essentially radially inwardly extending rim flanges. The present invention also relates to an apparatus for carrying out this method.
2. Description of the Prior Art
The beads of known tires of this type are mounted on rim seating surfaces which are disposed on the radially inner periphery of the rim ring next to the rim flanges, which extend radially inwardly, as shown, for example, in German Offenlegungsschrift No. 30 00 428. Consequently, the seating surfaces, which provide for an airtight mounting of the tire beads on the rim, are disposed in the radially and axially outer regions of the tire beads, i.e. in the interior of the tire.
With conventional vulcanizing apparatus, externally disposed tire surfaces are shaped by metallic mold parts, against which the tire surfaces are pressed via a bellows-like bag disposed in the interior. However, with a flexible expandable bellows-like bag, it is not possible to provide the described sealing surfaces in the interior of the tire with the required smooth surface.
German Offenlegungsschrift No. 32 46 624 describes apparatus with which tires of the aforementioned general type can be vulcanized. With this apparatus, however, it is necessary to fold or displace the tire side walls and the beads laterally outwardly into a so-called trapezoidal position for vulcanization in order to avoid undercuts. As a result of vulcanization in the trapezoidal position, and the necessary pivoting of the tire side walls and the beads during mounting, considerable extension results in the outer portion of the side walls and considerable compression results in the inner portions of the side walls, as a result of which with multi-ply carcasses the inner carcass ply can be completely relieved and hence practically ineffective. Due to the necessary pivoting process, it is also nearly impossible to utilize reinforcing components, especially in the bead region. A tire vulcanized in this manner can be mounted upon a rim only under stress, whereby the structural stability during operation suffers.
An object of the present invention, for tires of the aforementioned general type, is to provide a vulcanization method with which the tire can be vulcanized in such a way that it can subsequently be mounted upon a rim without permanent stresses.